Its definitely not A or D because there are 26 weeks in 6 months.
generally, a weight loss of 1-2 lbs per week is reasonable and safe.
I would say B because it is unrealistic that someone would always lose 2lbs a week
During a controlled experiment, a scientist will isolate and test (D) a single variable. A conclusion, nor a mass of information can be isolated or tested. A control group is the group that would receive a placebo, so testing that would be futile.
